I have found out what I was doing wrong to cause my wordpress plugin to throw up an error and it was this: On activation you put a piece of code that says
register_activation_hook(__FILE__,'install_function');
which basically means when the plugin is activated run the install_function. Problem turned out that I the function but hadn't named it correctly so the register_activation_hook wasn't looking for the right thing. I love it when I can work out how to solve things, and in the process learn a bit more about how to write a good plugin. Happy Days!